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<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a>
<FONT color="green">003</FONT>     * contributor license agreements.  See the NOTICE file distributed with<a name="line.3"></a>
<FONT color="green">004</FONT>     * this work for additional information regarding copyright ownership.<a name="line.4"></a>
<FONT color="green">005</FONT>     * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a>
<FONT color="green">006</FONT>     * (the "License"); you may not use this file except in compliance with<a name="line.6"></a>
<FONT color="green">007</FONT>     * the License.  You may obtain a copy of the License at<a name="line.7"></a>
<FONT color="green">008</FONT>     *<a name="line.8"></a>
<FONT color="green">009</FONT>     *     http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a>
<FONT color="green">010</FONT>     *<a name="line.10"></a>
<FONT color="green">011</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a>
<FONT color="green">012</FONT>     * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a>
<FONT color="green">013</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a>
<FONT color="green">014</FONT>     * See the License for the specific language governing permissions and<a name="line.14"></a>
<FONT color="green">015</FONT>     * limitations under the License.<a name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    package org.apache.commons.configuration.tree;<a name="line.17"></a>
<FONT color="green">018</FONT>    <a name="line.18"></a>
<FONT color="green">019</FONT>    <a name="line.19"></a>
<FONT color="green">020</FONT>    /**<a name="line.20"></a>
<FONT color="green">021</FONT>     * &lt;p&gt;<a name="line.21"></a>
<FONT color="green">022</FONT>     * A concrete combiner implementation that is able to construct an override<a name="line.22"></a>
<FONT color="green">023</FONT>     * combination.<a name="line.23"></a>
<FONT color="green">024</FONT>     * &lt;/p&gt;<a name="line.24"></a>
<FONT color="green">025</FONT>     * &lt;p&gt;<a name="line.25"></a>
<FONT color="green">026</FONT>     * An &lt;em&gt;override combination&lt;/em&gt; means that nodes in the first node<a name="line.26"></a>
<FONT color="green">027</FONT>     * structure take precedence over nodes in the second, or - in other words -<a name="line.27"></a>
<FONT color="green">028</FONT>     * nodes of the second structure are only added to the resulting structure if<a name="line.28"></a>
<FONT color="green">029</FONT>     * they do not occur in the first one. This is especially suitable for dealing<a name="line.29"></a>
<FONT color="green">030</FONT>     * with the properties of configurations that are defined in an<a name="line.30"></a>
<FONT color="green">031</FONT>     * {@code override} section of a configuration definition file (hence the<a name="line.31"></a>
<FONT color="green">032</FONT>     * name).<a name="line.32"></a>
<FONT color="green">033</FONT>     * &lt;/p&gt;<a name="line.33"></a>
<FONT color="green">034</FONT>     * &lt;p&gt;<a name="line.34"></a>
<FONT color="green">035</FONT>     * This combiner will iterate over the second node hierarchy and find all nodes<a name="line.35"></a>
<FONT color="green">036</FONT>     * that are not contained in the first hierarchy; these are added to the result.<a name="line.36"></a>
<FONT color="green">037</FONT>     * If a node can be found in both structures, it is checked whether a<a name="line.37"></a>
<FONT color="green">038</FONT>     * combination (in a recursive way) can be constructed for the two, which will<a name="line.38"></a>
<FONT color="green">039</FONT>     * then be added. Per default, nodes are combined, which occur only once in both<a name="line.39"></a>
<FONT color="green">040</FONT>     * structures. This test is implemented in the {@code canCombine()}<a name="line.40"></a>
<FONT color="green">041</FONT>     * method.<a name="line.41"></a>
<FONT color="green">042</FONT>     * &lt;/p&gt;<a name="line.42"></a>
<FONT color="green">043</FONT>     * &lt;p&gt;<a name="line.43"></a>
<FONT color="green">044</FONT>     * As is true for the {@link UnionCombiner}, for this combiner<a name="line.44"></a>
<FONT color="green">045</FONT>     * list nodes are important. The {@code addListNode()} can be called to<a name="line.45"></a>
<FONT color="green">046</FONT>     * declare certain nodes as list nodes. This has the effect that these nodes<a name="line.46"></a>
<FONT color="green">047</FONT>     * will never be combined.<a name="line.47"></a>
<FONT color="green">048</FONT>     * &lt;/p&gt;<a name="line.48"></a>
<FONT color="green">049</FONT>     *<a name="line.49"></a>
<FONT color="green">050</FONT>     * @author &lt;a<a name="line.50"></a>
<FONT color="green">051</FONT>     * href="http://commons.apache.org/configuration/team-list.html"&gt;Commons<a name="line.51"></a>
<FONT color="green">052</FONT>     * Configuration team&lt;/a&gt;<a name="line.52"></a>
<FONT color="green">053</FONT>     * @version $Id: OverrideCombiner.java 1301991 2012-03-17 20:18:02Z sebb $<a name="line.53"></a>
<FONT color="green">054</FONT>     * @since 1.3<a name="line.54"></a>
<FONT color="green">055</FONT>     */<a name="line.55"></a>
<FONT color="green">056</FONT>    public class OverrideCombiner extends NodeCombiner<a name="line.56"></a>
<FONT color="green">057</FONT>    {<a name="line.57"></a>
<FONT color="green">058</FONT>        /**<a name="line.58"></a>
<FONT color="green">059</FONT>         * Constructs an override combination for the passed in node structures.<a name="line.59"></a>
<FONT color="green">060</FONT>         *<a name="line.60"></a>
<FONT color="green">061</FONT>         * @param node1 the first node<a name="line.61"></a>
<FONT color="green">062</FONT>         * @param node2 the second node<a name="line.62"></a>
<FONT color="green">063</FONT>         * @return the resulting combined node structure<a name="line.63"></a>
<FONT color="green">064</FONT>         */<a name="line.64"></a>
<FONT color="green">065</FONT>        @Override<a name="line.65"></a>
<FONT color="green">066</FONT>        public ConfigurationNode combine(ConfigurationNode node1,<a name="line.66"></a>
<FONT color="green">067</FONT>                ConfigurationNode node2)<a name="line.67"></a>
<FONT color="green">068</FONT>        {<a name="line.68"></a>
<FONT color="green">069</FONT>            ViewNode result = createViewNode();<a name="line.69"></a>
<FONT color="green">070</FONT>            result.setName(node1.getName());<a name="line.70"></a>
<FONT color="green">071</FONT>    <a name="line.71"></a>
<FONT color="green">072</FONT>            // Process nodes from the first structure, which override the second<a name="line.72"></a>
<FONT color="green">073</FONT>            for (ConfigurationNode child : node1.getChildren())<a name="line.73"></a>
<FONT color="green">074</FONT>            {<a name="line.74"></a>
<FONT color="green">075</FONT>                ConfigurationNode child2 = canCombine(node1, node2, child);<a name="line.75"></a>
<FONT color="green">076</FONT>                if (child2 != null)<a name="line.76"></a>
<FONT color="green">077</FONT>                {<a name="line.77"></a>
<FONT color="green">078</FONT>                    result.addChild(combine(child, child2));<a name="line.78"></a>
<FONT color="green">079</FONT>                }<a name="line.79"></a>
<FONT color="green">080</FONT>                else<a name="line.80"></a>
<FONT color="green">081</FONT>                {<a name="line.81"></a>
<FONT color="green">082</FONT>                    result.addChild(child);<a name="line.82"></a>
<FONT color="green">083</FONT>                }<a name="line.83"></a>
<FONT color="green">084</FONT>            }<a name="line.84"></a>
<FONT color="green">085</FONT>    <a name="line.85"></a>
<FONT color="green">086</FONT>            // Process nodes from the second structure, which are not contained<a name="line.86"></a>
<FONT color="green">087</FONT>            // in the first structure<a name="line.87"></a>
<FONT color="green">088</FONT>            for (ConfigurationNode child : node2.getChildren())<a name="line.88"></a>
<FONT color="green">089</FONT>            {<a name="line.89"></a>
<FONT color="green">090</FONT>                if (node1.getChildrenCount(child.getName()) &lt; 1)<a name="line.90"></a>
<FONT color="green">091</FONT>                {<a name="line.91"></a>
<FONT color="green">092</FONT>                    result.addChild(child);<a name="line.92"></a>
<FONT color="green">093</FONT>                }<a name="line.93"></a>
<FONT color="green">094</FONT>            }<a name="line.94"></a>
<FONT color="green">095</FONT>    <a name="line.95"></a>
<FONT color="green">096</FONT>            // Handle attributes and value<a name="line.96"></a>
<FONT color="green">097</FONT>            addAttributes(result, node1, node2);<a name="line.97"></a>
<FONT color="green">098</FONT>            result.setValue((node1.getValue() != null) ? node1.getValue() : node2<a name="line.98"></a>
<FONT color="green">099</FONT>                    .getValue());<a name="line.99"></a>
<FONT color="green">100</FONT>    <a name="line.100"></a>
<FONT color="green">101</FONT>            return result;<a name="line.101"></a>
<FONT color="green">102</FONT>        }<a name="line.102"></a>
<FONT color="green">103</FONT>    <a name="line.103"></a>
<FONT color="green">104</FONT>        /**<a name="line.104"></a>
<FONT color="green">105</FONT>         * Handles the attributes during a combination process. First all attributes<a name="line.105"></a>
<FONT color="green">106</FONT>         * of the first node will be added to the result. Then all attributes of the<a name="line.106"></a>
<FONT color="green">107</FONT>         * second node, which are not contained in the first node, will also be<a name="line.107"></a>
<FONT color="green">108</FONT>         * added.<a name="line.108"></a>
<FONT color="green">109</FONT>         *<a name="line.109"></a>
<FONT color="green">110</FONT>         * @param result the resulting node<a name="line.110"></a>
<FONT color="green">111</FONT>         * @param node1 the first node<a name="line.111"></a>
<FONT color="green">112</FONT>         * @param node2 the second node<a name="line.112"></a>
<FONT color="green">113</FONT>         */<a name="line.113"></a>
<FONT color="green">114</FONT>        protected void addAttributes(ViewNode result, ConfigurationNode node1,<a name="line.114"></a>
<FONT color="green">115</FONT>                ConfigurationNode node2)<a name="line.115"></a>
<FONT color="green">116</FONT>        {<a name="line.116"></a>
<FONT color="green">117</FONT>            result.appendAttributes(node1);<a name="line.117"></a>
<FONT color="green">118</FONT>            for (ConfigurationNode attr : node2.getAttributes())<a name="line.118"></a>
<FONT color="green">119</FONT>            {<a name="line.119"></a>
<FONT color="green">120</FONT>                if (node1.getAttributeCount(attr.getName()) == 0)<a name="line.120"></a>
<FONT color="green">121</FONT>                {<a name="line.121"></a>
<FONT color="green">122</FONT>                    result.addAttribute(attr);<a name="line.122"></a>
<FONT color="green">123</FONT>                }<a name="line.123"></a>
<FONT color="green">124</FONT>            }<a name="line.124"></a>
<FONT color="green">125</FONT>        }<a name="line.125"></a>
<FONT color="green">126</FONT>    <a name="line.126"></a>
<FONT color="green">127</FONT>        /**<a name="line.127"></a>
<FONT color="green">128</FONT>         * Tests if a child node of the second node can be combined with the given<a name="line.128"></a>
<FONT color="green">129</FONT>         * child node of the first node. If this is the case, the corresponding node<a name="line.129"></a>
<FONT color="green">130</FONT>         * will be returned, otherwise &lt;b&gt;null&lt;/b&gt;. This implementation checks<a name="line.130"></a>
<FONT color="green">131</FONT>         * whether the child node occurs only once in both hierarchies and is no<a name="line.131"></a>
<FONT color="green">132</FONT>         * known list node.<a name="line.132"></a>
<FONT color="green">133</FONT>         *<a name="line.133"></a>
<FONT color="green">134</FONT>         * @param node1 the first node<a name="line.134"></a>
<FONT color="green">135</FONT>         * @param node2 the second node<a name="line.135"></a>
<FONT color="green">136</FONT>         * @param child the child node (of the first node)<a name="line.136"></a>
<FONT color="green">137</FONT>         * @return a child of the second node, with which a combination is possible<a name="line.137"></a>
<FONT color="green">138</FONT>         */<a name="line.138"></a>
<FONT color="green">139</FONT>        protected ConfigurationNode canCombine(ConfigurationNode node1,<a name="line.139"></a>
<FONT color="green">140</FONT>                ConfigurationNode node2, ConfigurationNode child)<a name="line.140"></a>
<FONT color="green">141</FONT>        {<a name="line.141"></a>
<FONT color="green">142</FONT>            if (node2.getChildrenCount(child.getName()) == 1<a name="line.142"></a>
<FONT color="green">143</FONT>                    &amp;&amp; node1.getChildrenCount(child.getName()) == 1<a name="line.143"></a>
<FONT color="green">144</FONT>                    &amp;&amp; !isListNode(child))<a name="line.144"></a>
<FONT color="green">145</FONT>            {<a name="line.145"></a>
<FONT color="green">146</FONT>                return node2.getChildren(child.getName()).get(0);<a name="line.146"></a>
<FONT color="green">147</FONT>            }<a name="line.147"></a>
<FONT color="green">148</FONT>            else<a name="line.148"></a>
<FONT color="green">149</FONT>            {<a name="line.149"></a>
<FONT color="green">150</FONT>                return null;<a name="line.150"></a>
<FONT color="green">151</FONT>            }<a name="line.151"></a>
<FONT color="green">152</FONT>        }<a name="line.152"></a>
<FONT color="green">153</FONT>    }<a name="line.153"></a>




























































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